Technical Abstract: Breadfruits have high starch content and are a staple food in many tropical regions. They are normally roasted, baked, fried or boiled before consumption. To extend uses of breadfruits and take advantage of their high starch content, this research explored the feasibility of producing 100% breadfruit crispy-expanded snack products using breadfruit flour through twin screw extrusion. The objective of this study was to determine the effect of extrusion processing parameters on extruded product quality. The studied processing parameters were barrel temperatures (120-160°C), feeding rates (13-25 kg/h), screw speeds (287.5-437.5 rpm) and moisture contents of breadfruit flour (13-25%). The examined product quality indicators included expansion ratio, bulk density, color, crispness, hardness, water absorption index and water solubility. A central composite experimental design with 36 experiments was used. The results showed that the crispness of extruded products was positively correlated to the density and hardness. The high quality products had medium hardness, as well as relatively low density and crispy values, which can be achieved by using the extrusion conditions with barrel temperatures of 140-150°C, feeding rates of 19-22 kg/h, screw speeds of 325-362.5 rpm and moisture contents of 19-22%. Based on sensory evaluation results, the highest quality product, with acceptable flavor profile, was produced using a barrel temperature of 140°C, feeding rate of 19 kg/h, screw speed of 362.5 rpm and moisture content of 19%.